linux-kernel - Re: [feature] automatically detect hung TASK

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20071202185945.GA25990@elte.hu>
Date:	Sun, 2 Dec 2007 19:59:45 +0100
From:	Ingo Molnar <mingo@...e.hu>
To:	Andi Kleen <andi@...stfloor.org>
Cc:	linux-kernel@...r.kernel.org,
	Andrew Morton <akpm@...ux-foundation.org>,
	Arjan van de Ven <arjan@...radead.org>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [feature] automatically detect hung TASK_UNINTERRUPTIBLE tasks


* Andi Kleen <andi@...stfloor.org> wrote:

> Ingo Molnar <mingo@...e.hu> writes:
> 
> > this patch extends the soft-lockup detector to automatically
> > detect hung TASK_UNINTERRUPTIBLE tasks. Such hung tasks are
> > printed the following way:
> 
> That will likely trigger anytime a hard nfs/cifs mount loses its 
> server for 120s. To make this work you would need a new 
> TASK_UNINTERRUPTIBLE_EXTERNAL_EVENT or similar and mark all the places 
> which depend on those.

TASK_KILLABLE should be the right solution i think.

> I've also seen kernel modules that use semaphores like wait queues 
> While that gives a little funny results (high load average) it worked 
> so far, until this patch.

it still works with this patch of course. With a funny results like high 
load average _AND_ a clear debug message that tells us (and the user) 
where that high load average comes from.

	Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/